Method for feeding and directing reaction gas and solids into a smelting furnace and a multiadjustable burner designed for said purpose

ABSTRACT

The invention relates to a method for adjusting the flow velocity of reaction gas and the dispersion air of pulverous solids when feeding reaction gas and finely divided solids to the reaction shaft ( 6 ) of a suspension smelting furnace for creating a controlled and adjustable suspension. Reaction gas ( 8 ) is fed into the furnace from around a finely divided solid material flow ( 5 ), so that said solids are distributed with an orientation towards the reaction gas by means of dispersion air. The flow velocity and discharge direction of the reaction gas to the reaction shaft are adjusted steplessly by means of a specially shaped adjusting member ( 10 ) moving vertically in the reaction gas channel ( 13 ) and by means of a specially shaped cooling block ( 12 ) surrounding the reaction gas channel ( 13 ) and located on the arch of the reaction shaft. The velocity of the reaction gas is adjusted to be suitable, irrespective of the desired gas quantity, in the discharge orifice ( 14 ) located at the bottom edge of the reaction shaft arch ( 11 ), and from said orifice the gas is discharged into the reaction shaft ( 6 ) and forms there a suspension with the pulverous material, and the dispersion air needed for dispersing said material is adjusted according to the supply of the pulverous material. The invention also relates to a multiadjustable burner for realizing the method.

The present invention relates to a method for feeding reaction gas andfinely divided solids to a suspension smelting furnace, so that the flowvelocity and flowing direction of the reaction gas and solids areadjusted at a point where the reaction gas and solids are dischargedinto the suspension smelting furnace. The invention also relates to amultiadjustable burner for realizing the method.

The reaction shaft of a suspension smelting furnace is vertical, and itis necessary to form a good, i.e. controlled and adjustable suspensionin between the finely divided solids and reaction gas to be feddownwardly in at the top part thereof, in order to achieve for thesolids a combustion that is as complete as possible. A prerequisite forthe formation of a good suspension is that the suspension is not formeduntil the reaction space, i.e. the reaction shaft.

The finely divided solids to be fed into the suspension smelting furnacecan be dispersed and distributed into the reaction shaft for instance byusing a central jet distributor described in the GB patent 1,569,813. Bymeans of said distributor, the orientation of the solids that first flowfreely downwards is turned to an almost horizontal, outwardly directionprior to discharging solids into the reaction shaft. The solids aredirected outwards by using a curved glide surface in the distributor anddispersion air jets directed outwardly from underneath said surface.Reaction gas is fed into the outwardly directed solids flow. The finelydivided solid material is most often a concentrate.

In a normal situation, said central jet distributor with fixedperforations is sufficient; however, the use of concentrates that aredifficult to make react is becoming increasingly common, and therefore aneed has arisen to change dispersion also in other ways than by alteringthe amount of dispersion air. Because the dispersion air perforation inthe concentrate distributor proper is located in the reaction space,i.e. in the reaction shaft itself, the conditions are fairly demanding,and because the perforations are also located far away and at the end ofnarrow channels, it is not sensible to adjust the sizes ofperforations—at least not in continuous operation.

In the prior art there is known a method described in the U.S. Pat. No.5,133,801, where on the central axis of a central jet distributor thereis applied a vertical oxygen lance, through which oxygen is fed 5 . . .15% of the total amount of oxygen. Said lance is tubular in shape, sothat therein the discharge velocity and orientation of the oxygen intothe furnace are, owing to the straight, stationary model, determinedaccording to the quantity of oxygen only. Oxygen is mainly used asadditional oxygen for the concentrate, to boost the reactions from themiddle of the cloud of concentrate distributed by the concentratedistributor.

Generally the oxygen or oxygen-bearing gas, such as air, serving as thereaction gas, is first fed into the furnace in horizontal direction, butthe gas direction must be turned to vertical prior to its feeding to thereaction shaft. The changing of the direction of the reaction gas isdescribed in the U.S. Pat. No. 4,392,885. According to this patentdescribing a directional burner, the reaction gas is fed from around apulverous solid material in an annular flow to the furnace reactionshaft through a discharge orifice with a fixed cross-sectional area.

In a normal situation it suffices to have a burner with a stationarydischarge orifice for the reaction gas, but because current usageincreasingly favors nearly 100% oxygen, gas quantities have been reducedto a roughly fifth part of the previous air supply. Consequently, inorder to reach a given velocity for the reaction gas there is requiredan increasingly diminishing cross-sectional flow area for the dischargeorifice of the burner. It is a fairly common requirement for the burnerthat it must be feasible for running a relatively wide range as forcapacity and oxygen-enrichment. Because the reactions and conditions inthe furnace require a certain velocity range for the reaction gas in thereaction shaft, the use of a burner with a fixed orifice leads tooutside said range of acceptability. Consequently, current technologyrequires that the cross-sectional area of the reaction gas orifice inthe burner is adjustable.

The adjusting of the reaction gas discharge orifice as such is not aproblem, and there are several different ways to perform the task. Theproblem is to find a way of adjustment which, in addition to working ina desired fashion, also endures the rough furnace conditions, i.e thetemperature (about 1400° C.), has good mechanical strength (for instancefor the removal of possible build-ups with a rod), etc.

A stepwise adjustment is performed for example in a fashion described inthe U.S. Pat. Nos. 5,362,032 and 5,370,369 or in the FI patentapplication 932458. In the first of said patents, around the concentratedistributor there are provided two cocentric annular rings of differentsizes for the reaction gas. By conducting the gas to either or bothrings, there are obtained three fixed discharge velocity areas. In thesecond patent, a desired number of discharge pipes of a desired size areclosed or put to use. In the third there are “dropped” a suitable numberof funnel-shaped open cones according to the case. All embodiments,however, are characterized by their stepwise nature, which means that itis not possible to bind the adjustment for instance to capacity in acontinuous process.

Continuously operated systems of adjustment are described in the U.S.Pat. Nos. 4,490,170 and 4,331,087. In both systems, adjusting is basedon changing the rotation power of the reaction gas, and is thus notsuitable for adjusting linear velocity only.

The Japanese patent application 5-9613 utilizes a continuously operatedadjustment for the reaction gas. In this application, the adjustment isa closed cone structure that moves vertically around the concentratepipe. A reducing cone that leads reaction gas into the cylindricaldischarge orifice of the burner serves as the counterpiece of saidclosed cone. The cones that form the flow channel are both straight(i.e. the surface wall is straight) and equiangular, so that the gas isdirected to the concentrate falling in the cylinder before it reachesthe distributor cone attached to the oil lance installed inside theconcentrate pipe. Thus the adjusting operations are clearly carried outbefore the concentrate and the reaction gas are discharged into thefurnace, and while discharging into the furnace, the reaction gas thatis partly mixed into the concentrate has lost the velocity (anddirection) it achieved through the adjustment, i.e. the dischargevelocity into the furnace is determined according to the fixed dischargeorifice of the burner. The direction of the adjustment is always thesame: powerfully towards the middle axis, never parallel to the axis oroutwards therefrom.

The above described mixing of reaction gas and concentrate carried outinside the burner is not possible with pure oxygen or with a highoxygen-enrichment, if the concentrate is easily reacting, because inthat case the result is the blocking of the burner due to the sinteringof the concentrate. From the point of view of adjustment, the burneroperates, with respect to the furnace space, in similar fashion as anyburner with a fixed orifice. Said patent application also introduces theuse of oxygen and/or oil in a concentrate burner in the middle of theconcentrate flow, but it does not describe in more detail any featuresaffecting the discharge of said oxygen and/or oil.

In the method according to the present invention, the adjusting of thereaction gas velocity, and particularly of its direction as well, takesplace in a reaction gas channel located around the finely divided solidsflow, in which channel there is installed a vertically moving, annularand custom-shaped adjusting member. The adjusting member is connected toan adjusting device proper, which reacts to changes in the capacityand/or in the oxygen enrichment and moves the adjusting memberaccordingly. Advantageously the adjusting member is cooled, because itextends to the reaction space when running with a small capacity. Theadjusting of the velocity and direction of the reaction gas are alsoaffected by a shaped cooling block located on the arch of the reactionshaft, around the reaction gas channel. The cross-sectional andtransversal area and direction of the reaction gas are adjusted to besuch as is desired, particularly at the gas discharge orifice throughwhich the gas is discharged to the reaction shaft of the suspensionsmelting furnace. The adjusting of the velocity and direction of thedispersion air takes place in two steps, i.e. air is distributed intothe two channels of the distributor. The topmost perforations locatednearest to the concentrate flow are designed for a normal case. When thecapacity grows, dispersion air can be added through additionalperforations that are located underneath said perforations andadvantageously directed downwards. Additional fuel is fed with a lancefrom the middle of the central jet distributor. The oxygen needed forthe combustion of the additional fuel is in advance divided into twoparts, i.e. there are two channels leading to the distributor, andoxygen gas can be fed through said channels, either through both or onlyone of them. The velocity is adjusted owing to the special arrangementprovided in the discharge orifice. The essential novel features of theinvention are apparent from the appended patent claims.

In the multiadjustable burner according to the invention, the reactiongas that is turned essentially in the direction of the reaction shaftflows in the reaction gas channel which surrounds in an annular fashionthe solids supply pipe located in the middle of the burner and in theend flows, according to the present invention, to the reaction shaft,adjusted to a desired velocity and direction, through the dischargeorifice. The adjusting takes place by means of a vertically operatedadjusting member, which again is located in a ring-like fashion at theinner edge of the reaction gas channel, thus surrounding the solidssupply pipe. Consequently the continuous, steppless adjusting of thedischarge orifice of the reaction gas channel takes place in oneannulus.

The flow direction of the reaction gas, and at the same time the meetingpoint of the reaction gas and the concentrate flow, is determined bymeans of the design of the adjusting member. As for the dischargevelocity, it is adjusted according to the invention by moving theadjusting member vertically, so that at the very bottom edge of thereaction shaft arch, there is always adjusted the narrowest spot thatdetermines the discharge velocity of the reaction gas. Consequently,according to this invention, the cross-sectional flow area of thereaction gas to be fed into the reaction shaft is continuously reducedas far as the discharge orifice located at the bottom edge of the arch.The point of adjustment always remains in the same spot, i.e. at thebottom edge of the arch, but the cross-sectional area of the dischargeorifice changes steplessly along with the adjusting process. This ismade possible by a cooling block located on the arch, by a water-cooledadjusting member and likewise a watercooled concentrate distributor,advantageously a central jet distributor extending as far as thereaction shaft. All these are essential factors in order to achieve acontrolled discharge from the burner—which is required for obtaining agood suspension and for preventing the formation of build-ups—and morespecifically so that it is most effective in the reaction space itself,i.e. in the reaction shaft, and not, like in many prior art adjustingmethods, so that the gas discharge is most effective inside the burnerand has already lost power when entering the reaction space from thedischarge orifice. It is most advantageous to adjust the reaction gasflow direction to be either parallel to the central axis of the reactionshaft, or to be directed towards the central axis.

There are several reasons for directing the reaction gas. It is wellknown that the velocity of the gas jet, for instance on its centralaxis, decreases in a linear fashion as a function of the distance and isdirectly proportional to the diameter of the discharge orifice. When thequantity of the reaction gas is reduced, the discharge orifice must alsobe reduced owing to the reasons stated above. The size of a nozzle ofthis type is diminished when the discharge orifice is reduced in orderto maintain the velocity of the reaction gas at the reaction point.

One possible way to maintain the velocity difference between theconcentrate and the reaction gas flow is to shorten the distance betweenthe discharge orifice and the meeting point of said medium substances.This is achieved by changing the direction of the reaction gas flow. Ifit is desired that the meeting point be always the same, the reactiongas flow must be directed according to the changes in the starting pointof the discharge orifice.

In some more difficult cases it may be advantageous to direct thereaction gas flow somewhat outwards, so that also the meeting point isshifted further from the central axis and thus from the burner itself.This type of directing is used for instance when the reaction activityshould be moved “further” from the burner. It is typical of this type ofmethod for adjusting velocity and direction that both velocity anddirection can be controlled in any point of adjustment.

In an arrangement according to the present invention, the surface designboth with the adjusting member and the cooling block, which bothrestrict the reaction gas discharge channel, is advantageously such thatthe edge lines of the curved surfaces are not linear but curved. Thedesign is such that the cross-sectional flow area of the annular channelis gradually turned to a desired direction when approaching thedischarge orifice. In aligning the cross-sectional surface, there isapplied the known principle of a continuous diminishing cross-sectionalsurface. The difference is that according to the present invention, thesize of the cross-sectional flow area is continuously adjustable, andthat the desired direction can still be maintained.

According to the present invention, the adjusting of the velocity andparticularly also of the direction of the dispersion air used fordispersing the concentrate flow thus takes place in two steps, i.e. airis divided into two channels already at the stage where it is fed intothe distributor. The topmost and also the smallest perforations (primaryair) that are located nearest to the concentrate flow to be distributedby means of the shaped body of the distributor are designed for a normalcase. Advantageously these perforations are provided in the horizontaldirection. When the capacity grows, distribution air can be addedthrough additional perforations (secondary air) provided underneath saidsmallest perforations; these are advantageously larger and directedmainly downwards. From the point of view of usage it is advantageousthat although other line of perforations is employed, an air current ofa certain degree (10%) must be allowed to flow through the other set ofperforations, too, so that a possible return flow and the blocking ofthe perforations is thus prevented.

The direction of the dispersion air flow, and at the same time itsmeeting point with the concentrate flow in the lower perforation, isnormally determined to fall in a spot in the concentrate flow which islocated somewhat after the meeting point of the air current dischargedfrom the upper perforations. Now a two-step dispersion of the suspensionis achieved. The lower perforations must be larger in order to maintaintheir velocity at least as high as that of the air discharged throughthe upper perforations, when the air currents meet the concentratesuspension.

According to the present invention, additional fuel, advantageouslyheavy oil, is fed for example by means of a commercial lance from thecenter of the central jet distributor. For instance pressurized air canbe used for dispersing it and cooling the lance. For the oxygen that isneeded in the combustion of oil, it is most advantageous to use pureoxygen, because the employed spaces are narrow. Naturally air oroxygen-enriched air can also be used, but these bring aboutdifficulties, because the burner size also grows. It is a normalphenomenon, particularly when smelting nickel concentrate in a flashsmelting furnace, that the need of additional fuel varies. Here we havethe same situation as with the pressurized air used for dispersing saidconcentrate: it is necessary to be able to adjust the gas dischargearea. Likewise we have exactly the same situation in adjusting it;adjustable perforation systems can be made, but it is not easy owing tothe length of the concentrate distributor (about two meters) and theclose fit of the special shaped distributor body. For this purpose,however, we have developed our own system which is fairly easy to use,as is apparent from the appended drawings. The system is further basedon preliminary oxygen distribution, i.e. there are two channels leadingto the distributor, into which channels we can feed oxygen gas eitherthrough both channels or only through one, but in any case so that asmall leak into the “unused” channel is allowed. The velocity ismaintained owing to a special arrangement in the discharge orifice, asis explained in more detail below.

The present invention fulfills both the reaction requirements(controlled velocity difference between the concentrate and thecombustion gas, controlled direction of the process gas and meeting withrespect to the concentrate flow) and practical requirements for runningthe process (simple, endures conditions, can be auto-mated for capacityvariations).

The invention is further described with reference to the appendeddrawings, where

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematical illustration of an embodiment of the presentinvention, i.e. a suspension smelting furnace,

FIG. 2 illustrates in vertical cross-section a reaction gas adjustingarrangement, located in the burner discharge orifice around theconcentrate distributor,

FIG. 3 shows three different positions of adjustment in order toillustrate the reaction gas adjusting process in FIGS. 3A, 3B and 3C,and

FIG. 4 illustrates in more detail a concentrate distributor according tothe invention and the apparatus for feeding oxygen or additional fuel.

FIG. 1 shows a suspension smelting furnace 1, whereto pulverous solids(concentrate) and fuel are fed through a concentrate burner 2, which inthis case is a multiadjustable burner according to the invention Theconcentrate is shifted from the tank 3 by means of a conveyor 4 to thetop part of the concentrate discharge channel 5, so that the materialfalls in a continuous flow via said channel 5 to the top part 7 of thereaction shaft 6 of the suspension smelting furnace 1. The reaction gas8 is conducted from around said concentrate channel 5, in an essentiallyparallel direction to the reaction shaft, to the top part 7 thereof.

In FIG. 2, the reaction gas (oxygen or oxygen-enriched gas such as air)is conducted to the burner and turned to flow mainly in the direction ofthe central axis 9 of the reaction shaft. The discharge direction of thegas 8 into the reaction shaft is adjusted by means of an adjustingmember 10 surrounding the concentrate channel 5 and by means of thedesign of the cooling block 12 located on the arch 11, and the dischargevelocity is adjusted by means of changing the cross-sectional area ofthe bottom part of the reaction gas channel 13 located in between theadjusting member 10 and the block 12. The final direction and velocityof the gas are determined at the bottom edge of the arch, in the annulardischarge orifice 14.

The adjusting device 15 installed above the arch reacts to capacitychanges and respectively moves the adjusting member 10 in the verticaldirection, so that the velocity and direction of the reaction air areadjusted steplessly. The adjusting member 10 is installed a ring-likefashion at the inner edge of the reaction gas channel. The surface ofthe adjusting member that is located on the side of the concentratechannel 5 conforms to the shape of the concentrate channel, but thesurface of the adjusting member 10 that is located towards the reactiongas channel 13 is designed so that it in all positions of the adjustingmember continuously reduces the cross-sectional flow area in the flowingdirection. The inner edge of the cooling block 12 that surrounds thereaction gas channel 13 in a ring-like fashion is likewise designed sothat it serves as the counterpiece for the adjusting member 10, so thatthe cross-sectional area of the reaction gas channel 13 ending at thedischarge orifice 14 is continuously reduced when proceeding downwards.

From the point of view of durability and feasibility, it is advantageousthat the block 12, the adjusting member 10 and the concentrate channel 5are cooled (for instance with water), because for example the adjustingmember 10 in its high position extends essentially as far as the bottomedge of the arch 11, and in its low position to inside the reactionshaft. Also the concentrate channel 5 extends to underneath the arch 11,to the reaction shaft. The cooling water circulation of the block ismarked with the reference number 16, the cooling of the dischargeorifice adjusting member with number 17 and the cooling of theconcentrate channel with number 18. An effective mixing effect that isadvantageous for the reactions is achieved by utilizing a concentratedistributor 19, to be described in more detail in FIG. 4, for turningthe direction of the pulverous material and for increasing its velocityand state of dispersion.

FIG. 3a illustrates a case where the capacity is normal, i.e. fairlynear to maximum. Now the adjusting member 10 is located relatively highand under a fairly low heat strain. The velocity conforms to the processrequirements and is for example 80 . . . 100 m/s. This design of thechannel directs the gas somewhat towards the central axis 9.

FIG. 3b illustrates a case where the capacity is smaller than normal,i.e fairly far from maximum. Now the adjusting member 10 is lowered, sothat the velocity can be maintained according to the processrequirements, for example at 80 . . . 100 m/s. This design of thechannel also directs the gas somewhat towards the central axis 9.

FIG. 3c introduces a case where the capacity is low, i.e fairly near tominimum Now the adjusting member 10 is lowered even further down, sothat the velocity can again be maintained according to the processrequirements, for example at 80 . . . 10 m/s. This design of the channelalso directs the gas somewhat towards the central axis 9.

According to FIG. 4, the concentrate distributor 19 is arranged insidethe concentrate channel 5, so that the tubular part 20 of theconcentrate distributor located within the concentrate channelcontinues, underneath the bottom edge of the concentrate channel, as acurved shaped body 21, which ends at the essentially horizontal terminaledge 22. The concentrate distributor is provided with a bottom plate 23.As is seen in FIG. 2, the bottom parts of both the concentrate channeland the concentrate distributor are located in the furnace space of thereaction shaft. The concentrate 24 falling down along the concentratechannel 5 meets the spreading and distributing stationary shaped surface21, owing to which the concentrate flow turns mainly horizontallyoutwards, thus forming an umbrella-like concentrate spray 25. Inaddition to the shaped surface, the turning of the concentrate flow isenhanced by means of perforations provided in the bottom edge of theshaped body. Through the holes in the perforation row 26, towards theconcentrate flow there is directed a dispersion air jet that turns thedirection of the concentrate. The perforations adjust the velocity ofsaid pressurized air according to the quantity of the concentrate. In anormal case the direction of the perforation is horizontally outwardsfrom the central axis of the distributor. When the concentrate flow isseparated from the shaped surface 21, it is collided by the dispersionair 27 discharging from the perforation row 26, so that the concentrateand the dispersion air are mixed together into a loose suspension andprovide the suspension with additional energy symmetrically towards theside. The dispersion and additional distribution of the concentratedepends on the impulse of the employed dispersion air, i.e. its quantityand velocity.

Additional energy is needed along with the growth of the concentratefeeding capacity. This may be achieved by increasing the dispersion airquantity, but if the air quantity is raised with a dispersion air systemprovided with fixed perforations, the required pressure risesunnecessarily high, wherefore it is advantageous to obtain additionalcross-sectional area for the perforation. In the present invention thisis, according to FIG. 4, arranged with an additional perforation row 28.Said additional perforations are arranged underneath the above describedperforation row 26, in the same distributor body. The holes in the lowerperforation row 28 are larger than the holes in the upper perforationrow 26, because it is known that this is a way to maintain the velocityof the discharging air jet higher than with smaller holes. This is dueto the fact that the air discharging from the lower perforation rowmeets the solids further away than the air jets discharging from theupper perforations. The meeting point of the concentrate and the airjets is shifted further by directing the holes of the perforation row 28somewhat downwards. The air jet 29 discharging from the lower holesfurther boosts the mixing of the jet discharged from the upper holes andthe concentrate. The final reaction is reached when the reaction gas,with adjusted velocity and direction, is discharged through the orifice14 to this dispersed concentrate suspension.

Suspension smelting, i.e. flash smelting, is generally autogenous, i.e.additional heat brought about by additional fuel is essentially notneeded, because the reactions between the concentrate and oxygen arevery exothermic. However, for practical reasons it is often necessary tofeed small amounts of additional fuel to the furnace. Among theaffecting factors let us point out the quality of the concentrate.Particularly when feeding nickel concentrate it is often necessary touse small amounts of additional fuel. Moreover, the feeding ofadditional fuel/nickel concentrate varies considerably, so that the fuelsupply must also be adjustable. Additional fuel, advantageously heavyfuel oil, is fed through a fuel pipe 30 installed in the middle of thedistributor and is injected into the furnace underneath the concentratedistributor, via a dispersing nozzle 31. For this purpose there areavailable suitable commercial nozzles with a sufficient range ofoperation for the capacity changes. The oil lance extends from themiddle of the distributor to the furnace space of the reaction shaft,wherefore it should be cooled; for the cooling, it is advantageous touse air that is discharged from around the lance via an annular pipe 32.

The quantity of oxygen required for the combustion of the additionalfuel is so large that the amount of cooling air is not sufficient, butin order to burn the oil it is necessary to feed oxygen into thefurnace, and the oxygen amount must be adjustable. In this case, whenoperating with a normal or small capacity, the required oxygen,so-called primary oxygen, is fed, through an annular channel 33surrounding the oil lance and its cooling air pipe, to several fixednozzles 34 attached at the far end of the channel, through which nozzlesthe oxygen is fed into the reaction shaft. The number of nozzles is3-12, advantageously 6-10, so that a jet-like effect is created. Thenozzles are located symmetrically around the fuel nozzle 31. From thenozzles 34 the primary oxygen is first discharged through secondaryholes 35 provided in the distributor bottom plate 23, underneath theprimary nozzles, to the furnace space. The holes 35 are somewhat largerthan the primary nozzles 34, i.e. to such extent that the dischargedprimary oxygen maintains its discharge velocity depending on thequantity and nozzle size, thus mixing to the oil spray dischargedthrough the oil nozzle 31 at a controlled space and thus forming acombustible oil mixture.

If there is need for additional combustion, the quantity of thesecondary oxygen that is fed mainly as a “leak” is increased in thesecondary oxygen channel 36 surrounding the primary oxygen channel 33.This addition is carried out so that in the discharge holes 35 of thissecondary oxygen channel, there is achieved nearly the same velocity asin the primary nozzles 34. Said velocity is determined according to thesum of the primary and secondary oxygen quantities and the area of thesecondary holes 35. Now the additional combustion with the correctvelocity of the combustion mixture is formed by said total oxygen.

EXAMPLE 1

Known concentrate burner systems are used in a flash smelting furnace,i.e. there are used the above described directional burner and centraljet distributor, as well as an oxygen lance arranged in the middle ofthe distributor. The concentrate is sulfidic copper concentrate, with aquantity of 50 t/h, with a sand addition of about 10%. The employedreaction gas is 98% oxygen gas, of which amount 5-15% is fed through thecentral lance of the distributor, and the rest through the directionalburner. When designed accordingly, the outer water-cooled shell of thecentral jet distributor is about ø 500 mm. This means that in order toachieve a sensible discharge velocity, the size obtained for theaperture of the annulus—that has a diameter of a good 500 mm—in thedischarge orifice of the directional burner is about 20 mm. This alsomeans that in order to avoid asymmetry, the discharge orifice structuresmust be solid and accurately centered.

If for some reason it is impossible to use so high oxygen-enrichment,but the combustion gas must be replaced with air, this first of allmeans that the quantity of reaction gas is increased five times. When itis also taken into account that the air must be preheated up to at least200° C., the reaction gas discharge velocity to the shaft will rise,with said burner with a fixed orifice and with the same capacity, toroughly eight-fold. This velocity is in many senses too high. Amongother things, pressure requirements for the reaction gas increase to anorder of 40 times as high as earlier. There is often no otheralternative than to decrease the capacity, so that a sensible runningarea is achieved.

Let us now use the method and burner according to the present invention.When running with a high oxygen-enrichment, adjustment is carried out sothat the adjusting member 10 is low (FIG. 3c), so that the aperture 14of the annular discharge orifice is of the order 20 mm and velocity onthe level of said normal burner. When air must be used with preliminaryheating, the adjusting member is raised higher (FIG. 3a or 3 b), so thatsaid aperture 14 at the bottom end of the discharge is of the order 50 .. . 60 mm, and the obtained velocity is rendered moderate again.

EXAMPLE 2

This example describes the adjusting of the quantity of oxygen to be fedfrom around an oil lance arranged inside a concentrate distributor 19.The excellent functionality of the method and apparatus according to theinvention for adjusting the velocity of the oxygen needed for burningthe oil is best apparent from the following series of measurements. Theaim is to adjust the velocity with a fixed oxygen discharge arrangementthat is located inside a shaped body used for concentrate distributionand is opened at the bottom, around the oil lance 31. From the point ofview of the reactions between the concentrate, oil and oxygen it isimportant that the oxygen velocity can be maintained sufficiently high.It is a difficult task, because we are talking about closed quarters anda high temperature in the reaction shaft, and the concentrate tends tobe easily sintered to the apertures if there is no gas flow towards thefurnace. Therefore any mechanical adjusting of the aperture size is outof question, as are apertures that should be utilized only from time totime.

According to the present invention, the multiadjustable burner can alsobe

utilized in critical areas, i. e. with low and high capacity. The oxygensupply needed by the additional fuel is taken care of by feeding theoxygen via the primary oxygen channel 33, and high capacity by feedingoxygen through both the primary and secondary oxygen channel 36. With alow capacity, the oxygen velocity is determined according to thevelocity (w=w_(s)=V_(s)/A_(s)) of the gas discharged from the nozzle 34located at the end of the primary channel 33, and thus not according tothe discharge hole 35. The subindex s refers to the nozzle 34. With highcapacity, the velocity is determined according to the gas velocity(w=w_(o)=(V_(s)+V_(o))/A_(o)), where the subindex o refers to thedischarge hole 35.

What is said above can be verified from the following series ofmeasurements, which for the sake of clarity was carried out with onepartial unit only (one nozzle 34 and one discharge hole 35).Accordingly, in the measurement there were two nested pipes, of whichthe outer and inner measures of the primary oxygen channel were ø30/20mm and of the secondary oxygen channel ø60/50 mm. The distance of thenozzle 34 from the discharge hole 35 was 20 mm, and the diameter of thedischarge hole 35 was 30 mm. The velocity was measured at a distance of105 mm from the discharge hole. In the table below, the letter S denotesto the primary oxygen channel, and the letter U denotes to the secondaryoxygen channel, the letter O denotes to the discharge hole and theletter X the point of measurement.

Particularly Table 2 proves the good functional properties of theinvention (the velocity w_(x)/corresponding feeding velocities w_(s),w_(u) and w_(o) measured at the distance 105 mm). In the cases 1 and 2,oxygen is fed only through the primary oxygen channel, and in the case 3also through the secondary oxygen channel, and as is seen from thistable, the gas velocities at the distance x are located in the same areairrespective of their quantity.

TABLE 1 Quantity Symbol Quality S U 0 X Cross-sectional area A mm² 3141257 707 Temperature T K 300 300 300 300 Gas flow 1 V_(n)1 m³/h 20 0 20Gas flow 2 V_(n)2 m³/h 10 0 10 Gas flow 3 V_(n)3 m³/h 20 40 60 Gasvelocity 1 w₁ m/s 19.4 0 8.6 9.5 Gas velocity 2 w₂ m/s 9.7 0 4.3 5.3 Gasvelocity 3 w₃ m/s 19.4 9.7 25.8 16.9

TABLE 2 Case w_(x)/w_(s) w_(x)/w_(u) w_(x)/w_(o) 1 0.49 infinite 1.10 20.55 infinite 1.23 3 0.87 1.74 0.66

What is claimed is:
 1. A method for adjusting flow velocity of reactiongas and dispersion air of pulverous solid material when feeding reactiongas and finely divided solids to a reaction shaft of a suspensionsmelting furnace for creating a controlled and adjustable suspension,where reaction gas is fed into the furnace from around a finely dividedsolid material flow, said solids being distributed with an orientationtowards the reaction gas by means of dispersion air, wherein the flowvelocity and discharge direction of the reaction gas to the reactionshaft are adjusted steplessly by means of a specially shaped adjustingmember moving vertically in a reaction gas channel and by means of aspecially shaped cooling block surrounding the reaction gas channel andlocated on an arch of the reaction shaft, so that the velocity of thereaction gas is adjusted to be suitable, irrespective of the gasquantity, in a discharge orifice located at a bottom edge of thereaction shaft arch, from which orifice the gas is discharged into thereaction shaft and forms there a suspension with the pulverous solidmaterial, and the dispersion air needed for dispersing said material isadjusted according to the supply of the pulverous solid material,wherein the adjusting member adjusting the cross-sectional area andorientation of the reaction gas flow is cooled, and wherein curvedsurfaces of the adjusting member and of the cooling block located on theside of the reaction gas channel are designed so as to reduce thecross-sectional flow area in the discharge direction of the reactiongas.
 2. A method according to claim 1, wherein the reaction gas flowvelocity is adjusted in one annulus.
 3. A method according to claim 1,wherein the direction of the reaction gas is adjusted to be turned awayfrom the central axis of the reaction shaft.
 4. A method according toclaim 1, wherein the direction of the reaction gas is adjusted to beparallel to the central axis of the reaction shaft.
 5. A methodaccording to claim 1, wherein primary dispersion air of the pulveroussolid materials is fed horizontally outwards from the central axis ofthe reaction shaft.
 6. A method according to claim 1, wherein secondarydispersion air of the pulverous solid material is fed in underneathprimary dispersion air.
 7. A method according to claim 1, whereinsecondary dispersion air of the pulverous solid material is fed in so asto be directed lower than primary dispersion air.
 8. A method accordingto claim 1, wherein fuel is fed into the reaction shaft from inside theflow of the pulverous solid material.
 9. A method according to claim 1,wherein oxygen is fed into the reaction shaft from inside the flow ofthe pulverous solid material.
 10. A method according to claim 1, whereinfuel and oxygen are fed into the reaction shaft from inside the flow ofpulverous solid material.
 11. A method according to claim 1, from insidethe flow of pulverous solid material, oxygen is fed in to the reactionshaft in an annular fashion from around a fuel supply.
 12. A methodaccording to claim 1, from inside the flow of pulverous solid material,oxygen is fed into the reaction shaft in two annular flows from around afuel supply.
 13. A method according to claim 1, by means of theadjusting member and the cooling block, the reaction gas velocity isadjusted to be constant.
 14. A multiadjustable burner for feedingreaction gas and fmely divided solid material into a reaction shaft,said burner comprising a distributor member located inside a pulveroussolids material discharge channel, said distributor member beingprovided with dispersion air perforations, and a reaction gas channelsurrounding the discharge channel in an annular fashion, wherein inorder to steplessly adjust flow velocity and direction of the reactiongas, the reaction gas channel is provided with a vertically movingannular adjusting member installed at an inner edge of the reaction gaschannel, wherein the adjusting member is provided with cooling means andthat on a reaction shaft arch there is arranged a cooling blocksurrounding the reaction gas channel, so that surfaces of the adjustingmember and the block that are located towards the reaction gas channelare in all positions of the adjusting member designed to adjust thecross-sectional flow area to be smallest in a discharge orifice locatedat a bottom edge of the arch, and that a distributor member of finelydivided material is underneath a shaped surface provided with two rowsof perforations.
 15. A multiadjustable burner according to claim 14,wherein the vertical motion of the adjusting member is created by meansof an adjusting device that is located on top of the arch and reacts tovariations in capacity and/or oxygen-enrichment.
 16. A multiadjustableburner according to claim 14, wherein the pulverous solid materialdischarge channel is provided with cooling means.
 17. A multiadjustableburner according to claim 14, wherein the adjusting member has a topposition and in its top position extends essentially as far as thebottom edge of the arch.
 18. A multiadjustable burner according to claim14, wherein the adjusting member extends to a top part of the reactionshaft.
 19. A multiadjustable burner according to claim 14, wherein anouter surface of the adjusting member and an inner surface of the blockare designed so that the reaction gas channel is directed away from thecentral axis of the reaction shaft.
 20. A multiadjustable burneraccording to claim 14, wherein an outer surface of the adjusting memberand an inner surface of the block are designed so that the reaction gaschannel is parallel to the central axis of the reaction shaft.
 21. Amultiadjustable burner according to claim 14, wherein an upper row ofperforations in the shaped body is directed essentially horizontally.22. A multiadjustable burner according to claim 14, wherein a lower rowof perforations of the shaped body is directed to be downwards inclined.23. A multiadjustable burner according to claim 14, wherein holes in alower perforation row of the shaped body are larger than holes in anupper perforation row.
 24. A multiadjustable burner according to claim14, wherein inside the concentrate distributor, there is installed afuel pipe (30) and a cooling air pipe surrounding it.
 25. Amultiadjustable burner according to claim 24, wherein around the fuelpipe and the cooling pipe installed inside the concentrate distributor,there is an annular primary oxygen channel.
 26. A multiadjustable burneraccording to claim 24, wherein around the fuel pipe and the cooling pipeinstalled inside the concentrate distributor, there are an annularprimary oxygen channel and an annular secondary oxygen channel.
 27. Amultiadjustable burner according to claim 25, wherein an outermost endof the primary oxygen channel is provided with nozzles (34).
 28. Amultiadjustable burner according to claim 25, wherein the distributorhas a bottom plate and the bottom plate of the distributor is providedwith secondary holes.
 29. A multiadjustable burner according to claim28, wherein the bottom plate of the distributor is provided withsecondary holes which are larger than holes in the primary nozzles.